The present invention relates to a handling system for feeding workpieces to a subsequent machining unit having a working area which is enclosed toward the outside by a protective wall and in which a stack presentation device is provided for presenting workpiece carriers with unmachined workpieces and for receiving workpiece carriers after the machining operation, and having a loading device assigned to the stack presentation device for delivering unmachined workpieces and for receiving workpieces after the machining operation.
Handling systems of this kind are principally known and are used for loading machine tools and the like. The stack presentation devices used in such systems normally consist of a pallet transfer system with two controlled axes in the horizontal and vertical directions to which workpiece carriers with unmachined workpieces can be fed via a conveyor from a space outside the working area while workpiece carriers with machined workpieces can be removed from the working area via another conveyor. Workpieces present in the stack presentation device are normally transferred to the loading device, which latter in most of the cases is configured as a gantry, from where the workpieces can be picked up one by one by means of grippers or the like and can be fed from the loading device to the subsequent machining unit, for example a machine tool. Upon completion of the machining operation, the machined workpieces are picked up again by the loading device and deposited on the workpiece carrier of the stack presentation device. The workpiece carriers, together with the machined workpieces, are then removed again from the working area via the conveyor.
It has been found to be a disadvantage of such handling systems that every time the workpiece carrier stack with the unmachined workpieces has been fully worked off in the working area, new workpiece carriers containing unmachined workpieces have to be fed in by means of the conveyor in order to avoid stoppages. This requires constant monitoring of the handling system and permits only limited automation of the process.